Underground irrigation or sprinkler systems have long been used to deliver water necessary to sustain growing plants and foliage. It is common for homeowners to have such sprinkler systems installed to support various landscaping amenities such as lawns, trees, shrubs, gardens and the like. However, installation of such sprinkler systems is laborious and can require complex irrigation routing to adequately provide for water delivery and drainage.
A conventional system for landscape watering comprises sprinkler heads that are arranged in an array over the watering area wherein each head is connected to a network of underground pipes that supply water. As illustrated in FIG. 1, present practice is to use conventional plumbing hardware, such as: rigid or semi-rigid fluid conduits such as a supply line 100, angle fittings 102, Tees 104, rigid risers 106, unions (not shown) and the like in order to connect the sprinkler head 108 to the water supply lines. However, this construction is subject to numerous problems and inconveniences. For example, laying out and accurately cutting the supply line, risers and arranging Tees, angles, etc., is very tedious and expensive in terms of labor costs and hardware.
An example of the disadvantages of present practice is the high degree of skill and the high cost of labor that is required to properly dig trenches, not only for the supply line, but also for the branches of pipe (risers) leading from the supply line to each sprinkler head. In general, it is necessary to dig straight and wide trenches for the supply line. However, this becomes virtually impossible because of rocks, tree roots, foundations, buried cables or other objects. Where such obstacles are encountered, the trench must be dug, typically by hand, around and adequately away from such objects. Then supply line must be cut to fit, and elbows, angles, Tees, risers, unions and the like are then glued or threaded in place.
Great care must be taken when trenching in order to avoid striking underground obstacles such as main water service lines, electrical service lines, gas service lines, etc. Various building codes frequently require trenches to reach up to 16″ to 24″ or more in depth to avoid freezing the supply line and other fittings. Deep trenches require a greater amount of labor, time and equipment to excavate. Also, to prevent costly damage by or to trenching tools and equipment, trenches must be dug at a reasonably safe and appropriate distance away from obstacles such as sidewalks, curbs, driveways, planting borders, and the like. Conversely, since most sprinkler heads are located within a few inches from sidewalks, curbs, driveways, etc., the remaining trenching to these locations is almost always done by hand. Then a series of fluid conduits are installed to reach from the supply line to the sprinkler heads.
One significant problem is that during assembly of conventional sprinkler systems, the supply line (sometimes referred to as a lateral line) is constantly being moved around in the trench during installation of various Tees, risers and sprinkler heads that are being attached along its length. For example, as each section of pipe is cut-to-length to install various components, the supply line is lifted out of the trench. As a result of moving the supply line during assembly any measuring errors may combine and thus leave a particular length of pipe shorter than expected. The time to measure, calculate, cut, assemble, and fasten becomes extensive. This process repeats itself when the next sprinkler head is to be attached. Frequently, while handling the supply line for the next sprinkler head assembly, the sprinkler head (or heads) previously assembled and set into place, will unavoidably be disturbed.
The supply line typically undulates along even the straightest of trenches frequently resulting in misalignment of the sprinkler heads. The sprinkler head placement needs to be in a predetermined, relatively regular array to give proper watering coverage without overlap, waste or gaps in coverage. Thus, when installing the various fixed-length fluid conduits (i.e., risers, transitions and sprinkler heads), the resulting final sprinkler head array is usually misaligned to some degree, often significantly so.
Further, sprinkler head arrays must be laid out in 3-dimensions. That is, the land is rarely flat, yet sprinkler heads must all be positioned properly with respect to ground level, which varies throughout the watering area. Irregularities in the ground surface and elevation present a problem when installing an underground irrigation system. It is normally desirable to have the sprinkler heads flush with the ground surface. However, with differences in the surface elevation and angle from the supply lines to the sprinkler head usually require the risers to be customized to compensate for the irregularities. The irrigation systems offered today simply do not permit proper sprinkler head placement without very careful layout and skilled assembly of parts and typically do not facilitate proper final sprinkler head adjustment.
A common method of addressing the irregular ground problem is shown in FIG. 2, which uses a flexible fluid delivery line, which is commonly referred to as a semi-flexible riser 200 to couple the sprinkler head 108 to the supply line 100 by way of a Tee fitting 104. The semi-flexible riser 200 must be bent and supported with soil and is usually difficult to position and unstable relative to the ground surface. After ground preparation, each sprinkler head that is not correctly positioned (i.e., higher, lower, or angled) is usually removed and repositioned. If the sprinkler head is angled or significantly out of alignment, a shim or volume of soil is positioned along side of the riser or sprinkler head to adjust the orientation of the sprinkler head. This procedure is time consuming, inaccurate, unreliable, and allows for contaminants (e.g., dirt) to be introduced into the system.
Additionally, the semi-flexible riser 200 usually has a threaded fluid coupling/connector or end fitting 202 at each end, see FIG. 2, which provides a fluid connection between the Tee 104 and the sprinkler head 108. One disadvantage of the semi-flexible riser 200 is the installation and/or removal of the sprinkler head 108.
Firstly, during removal of the sprinkler head 108, a turning, twisting or torquing force is applied to the sprinkler head 108 to thereby disengage the threads between the end fitting 202 and the sprinkler head 108. The turning force may loosen the end fittings at either end of the semi-flexible riser 200, which has the inherent risk of disconnecting the riser at the supply line/Tee junction 204 instead of at the riser/head junction 206. In the event that the semi-flexible riser 200 disconnects from the supply line/Tee junction 204, the riser 200 will need to be excavated all the way back to the Tee 104 and reconnected. This type of repair is time consuming and causes damage to established landscaping.
Secondly, during installation of the sprinkler head 108, a turning force is applied to the sprinkler head 108 which engages the treads between of the end fitting 202 and fluidly couples the sprinkler head with the riser 200. However, to properly attach and adequately seal the junction 206, the sprinkler head 108 typically requires substantial tightening with respect to the threads of the end fitting 202. Since the end fitting 202 is free to turn or twist the semi-flexible riser 200, properly tightening the sprinkler head 108 to the riser 200 is problematic. As a result, if the sprinkler head 108 is not adequately secured to the riser 200, the junction 206 will leak and may cause the sprinkler head 108 to detach from the riser 200.
Thirdly, during either installation or removal of the sprinkler head 108, the end fitting 202 may freely turn or twist the semi-flexible riser 200 when the sprinkler head 108 is turned. As a result, the sprinkler head 108 may not adequately engage/disengage the end fitting 202. In this situation, a larger excavation hole must be dug around the riser 200 so that the installer may separately grasp the end fitting 202 and sprinkler head 108 for installation/removal operations. This is disadvantageous because of additional time consumption, requiring the use of both hands and the potential for damaging established landscaping.
Current semi-flexible riser installation techniques create two additional problems. First, if the sprinkler head is displaced in a downward direction a serious leak may occur. For example, if the sprinkler head is stepped on or run over by maintenance equipment this will cause a downward displacement of the sprinkler head. This downward displacement breaks the internal seal created between a bushing inserted into the inner tube and the end fitting. Second, since the end fitting and sprinkler head are permitted to freely turn after installation, the sprinkler head may become misaligned with respect to the landscaping. For example, after installation, the sprinkler head may be stepped on or bumped by maintenance equipment. A result of the misaligned sprinkler head is that water is wasted and the landscaping is not adequately irrigated.
Consequently, efforts to provide an efficient, cost effective and convenient connection between the supply line and the sprinkler head of an irrigation system have not met with much success to date.